Breast Cancer (BRCA) Gene TestSkip to the navigation
A breast cancer (BRCA) gene test is a blood test to check for specific changes (mutations) in genes that help control normal cell growth. Finding changes in these genes, called BRCA1 and BRCA2, can help determine your chance of developing breast cancer and ovarian cancer . A BRCA gene test does not test for cancer itself. This test is only done for people with a strong family history of breast cancer or ovarian cancer, and sometimes for those who already have one of these diseases. Genetic counseling before and after a BRCA test is very important to help you understand the benefits, risks, and possible outcomes of the test.
A woman's risk of breast and ovarian cancer is higher if she has BRCA1 or BRCA2 gene changes. Men with these gene changes have an increased risk of breast cancer. And both men and women with these changes may be at an increased risk for other cancers. The gene changes can be inherited from either your mother's or father's side of the family.
You may be more likely to have a BRCA gene change if you: 1
- Were diagnosed with breast cancer before age 50.
- Have had breast cancer in both breasts.
- Have had breast cancer and ovarian cancer.
- Have one or more male family members who have had breast cancer.
- Have multiple cases of breast cancer in the family.
- Have at least one family member who has had BRCA-related cancer.
- Are an Ashkenazi Jew (a Jewish person whose ancestors came from Eastern Europe).
If you don't meet any of these criteria, you are not likely to have a BRCA1 or BRCA2 gene change. Only about 2 or 3 out of 1000 adult women have a BRCA gene change. 1
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Why It Is Done
If your family history or personal history indicates a high chance for breast cancer, a BRCA gene test is done to check your chance of developing this cancer.
A BRCA gene test does not test for cancer itself. It is used to help women who have a strong family history of breast or ovarian cancer find out if their chance is high enough to think about prevention measures before cancer develops. These measures include:
- Having screening tests (such as clinical breast exams , mammograms , and MRIs ) more often and starting them at an earlier age.
- Taking medicines such as tamoxifen or raloxifene.
- Having a preventive mastectomy .
- Having their ovaries removed (oophorectomy).
Men with a family history of BRCA changes also may want to be tested to find their chance of breast cancer.
For a woman who has ovarian cancer, or for a man or a woman who has breast cancer, results from a BRCA gene test can help other family members know their chances of these and perhaps other cancers. If the person with breast or ovarian cancer has normal BRCA gene test results, family members probably would not benefit from the BRCA genetic test.
How To Prepare
Genetic counseling is strongly recommended before and after a BRCA test to help you understand the benefits, risks, and possible outcomes of the test. A BRCA test gives you the chance to make informed medical and lifestyle decisions. Genetic counselors are trained to talk with you about the test and its results, including the medical information and your emotional concerns.
This test may cause you some worry, both before and after the test. Talk with a genetic counselor before the test to help you prepare for and cope with this worry. Think about what you may do if your test is positive. For example, would you consider any prevention measures, such as the following:
- For breast cancer: A yearly mammogram and/or an MRI , a clinical breast exam at regular times, preventive mastectomy (removal of both breasts), having your ovaries removed, taking a medicine (tamoxifen), or having your children before age 30
- For ovarian cancer: Having your ovaries removed (oophorectomy) after you are done having children, or after age 35
You will be asked to sign a consent form that says you understand the risks of the test and agree to have it done.
Talk to your doctor about any concerns you have regarding the need for the test, its risks, or how it will be done. To help you understand the importance of this test, fill out the medical test information form (What is a PDF document?) .
No other special preparation is needed before you have this test.
How It Is Done
The health professional drawing blood will:
- Wrap an elastic band around your upper arm to stop the flow of blood. This makes the veins below the band larger so it is easier to put a needle into the vein.
- Clean the needle site with alcohol.
- Put the needle into the vein. More than one needle stick may be needed.
- Attach a tube to the needle to fill it with blood.
- Remove the band from your arm when enough blood is collected.
- Apply a gauze pad or cotton ball over the needle site as the needle is removed.
- Apply pressure to the site and then a bandage.
How It Feels
The blood sample is taken from a vein in your arm. An elastic band is wrapped around your upper arm. It may feel tight. You may feel nothing at all from the needle, or you may feel a quick sting or pinch.
It is common to worry before a BRCA test and while waiting for its results.
There is very little chance of a problem from having a blood sample taken from a vein.
- You may get a small bruise at the site. You can lower the chance of bruising by keeping pressure on the site for several minutes.
- In rare cases, the vein may become swollen after the blood sample is taken. To treat this, you can use a warm compress several times a day.
- Ongoing bleeding can be a problem for people with bleeding disorders. Aspirin, warfarin (Coumadin), and other blood-thinning medicines can make bleeding more likely. If you have bleeding or clotting problems, or if you take blood-thinning medicine, tell your doctor before your blood sample is taken.
Some women may be worried about the test results and how it will affect their life insurance, disability insurance, or long-term care insurance.
Normal (called negative)
No changes were found in the BRCA1 or BRCA2 genes.
A negative result and your overall family risk must be considered together.
- If a family member has a known BRCA change, other family members may want to be tested.
- If your family member with breast or ovarian cancer tests negative for BRCA changes, you probably don't carry those changes, either. In this case, you have the same chance of cancer as that of the general public, based on your age and personal and family history.
Only about 5% to 10% of breast and ovarian cancers are linked to the BRCA1 or BRCA2 gene change. If you have a strong family history of breast or ovarian cancer, you may still have a higher chance of developing breast cancer even if you have a negative BRCA result. Other gene changes are possible that make cancer more likely.
Abnormal (called positive)
BRCA1 or BRCA2 gene changes are present.
Women who have BRCA1 or BRCA2 gene changes have about a 35% to 84% chance of developing breast cancer and between a 20% and 40% chance of developing ovarian cancer during their lifetimes. 2, 3 These numbers show a wide range of chance and depend on your other personal and family history.
Men with BRCA1 changes have a higher risk of breast cancer and possibly other cancers, such as pancreatic, testicular, or prostate cancer. Men with BRCA2 changes have an increased risk of breast, pancreatic, and prostate cancers. 2
Uncertain (called variant of uncertain significance or VUS)
This result may mean that a gene change is present but it is difficult for your doctor to know if the change is important and if it changes your chances of developing cancer.
What Affects the Test
Your doctor will talk with you about anything that may stop you from having the test or that may change the test results.
What To Think About
There are several important things to think about when you are making the decision to have a BRCA gene test.
- If you have a strong family history of breast cancer, a negative BRCA result does not mean that you will not develop breast cancer. BRCA1 and BRCA2 gene changes do cause a higher chance of breast cancer. But other gene changes are possible and may cause cancer.
- If you have a family member with breast cancer, think about asking the family member to be tested for a gene change before you have a test. If your family member's BRCA tests results are negative, it usually is not helpful to test the rest of the family.
- Most insurance companies will cover the cost of genetic testing for those who meet the conditions for testing.
- The discovery of a genetic disease that is not causing symptoms now (such as breast cancer) should not affect your future ability to gain employment or health insurance coverage. A law in the United States, called the Genetic Information Nondiscrimination Act of 2008 (GINA), protects people who have DNA differences that may affect their health. This law does not cover life insurance, disability insurance, or long-term care insurance.
- The United States Preventive Services Task Force (USPSTF) does not recommend BRCA testing for women who do not have family risk factors. 1
- For women from families that do not have risk factors for BRCA changes, a genetic test is not likely to give any useful information about their chance of developing breast cancer. Women from average-risk families rarely have a positive test. A BRCA gene test is not recommended for a person without risk factors, because the test can give a false-positive test result .
- Breast Cancer Risk: Should I Have a BRCA Gene Test?
- Breast Cancer: What Should I Do if I'm at High Risk?
Genetic counseling before and after a BRCA test will help you understand the benefits, risks, and possible outcomes of testing. A BRCA test gives you the chance to make informed medical and lifestyle decisions. To find doctors who do gene tests and counseling, call the cancer information service at the National Cancer Institute at 1-800-4-CANCER (1-800-422-6237). To find a genetic counselor near you, contact the National Society of Genetic Counselors at (312) 321-6834 or visit their website at www.nsgc.org.
Other Places To Get Help
- U.S. Preventive Services Task Force (2013). Risk assessment, genetic counseling, and genetic testing for BRCA-related cancer in women: U.S. Preventive Task Force recommendation statement. U.S. Preventive Services Task Force. http://www.uspreventiveservicestaskforce.org/uspstf12/brcatest/brcatestfinalrs.htm. Accessed March 6, 2014.
- National Cancer Institute (2009). BRCA1 and BRCA2: Cancer risk and genetic testing. Available online: http://www.cancer.gov/cancertopics/factsheet/Risk/BRCA.
- Fleming GF, et al. (2009). Epithelial ovarian cancer. In RR Barakat et al., eds., Principles and Practice of Gynecologic Oncology, 5th ed., pp. 763-835. Philadelphia: Lippincott Williams and Wilkins.
Primary Medical Reviewer Sarah Marshall, MD - Family Medicine
Specialist Medical Reviewer Douglas A. Stewart, MD - Medical Oncology
Current as ofApril 15, 2014
Current as of: April 15, 2014
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